Implantable pulse generators 15, such as pacemakers, defibrillators, implantable cardioverter defibrillators (“ICD”) and neurostimulators, provide electrotherapy via implantable medical leads 10 to nerves, such as those nerves found in cardiac tissue, the spinal column, the brain, etc. Electrotherapy is provided in the form of electrical signals, which are generated in the pulse generator 15 and travel via the lead's conductors to the electrotherapy treatment site.
Lead conductors 85 are typically in the form of flexible single wires or multi-filar cables. These lead conductors 85 may be individually electrically insulated with their own dedicated insulation jackets or may be without a dedicated insulation jacket, instead having to rely on the concentric insulation layers of the lead body.
New lead technologies and treatment programs make it desirable to place electronic lead components along the length of the lead body 50 of a lead 10. For example, as indicated in FIG. 1, which is an isometric view of a proposed lead body 50 that may be coupled to a pulse generator 15 via a lead connector end 35 having a pin contact 55 and ring contacts 61-62, multiple fragile electronic chips electrodes 80-83 may be located along the lengths of the conductors 85a, 85b, 85c extending between the proximal and distal ends 40, 45 of the lead body 50. The placement of such electronic chip electrodes 80-83 necessitates multiple closely spaced couplings of the straight-routed conductors 85a-85c with the terminals of the electronic chip electrodes 80-83. Such close spaced couplings with conductors 85a-85c substantially reduce the ability of the conductors 85a-85c to displace and conform to displacement of the lead body 50, potentially resulting in rapid failure of the conductors 85a-85c. Also, the conductors 85a-85c result in substantial strain in the couplings, causing rapid failure of the couplings as well.
There is a need in the art for a lead having a conductor configuration that provides improved resistance to strain induced conductor failure, reduced lead body stiffness and reduced manufacturing costs. There is also a need in the art for a method of manufacturing a lead having such a conductor configuration.